package common

import (
	"bytes"
)

/*
  StringBuilder struct.
  用于高效拼接字符串。
  示例用法：
	builder := NewStringBuilder()
	builder.Append("a").Append("b").Append("c")
	s := builder.ToString()
	println(s)
  输出：
	abc
*/

// StringBuilder 提供高效的字符串拼接功能。
type StringBuilder struct {
	buffer bytes.Buffer
}

// NewStringBuilderCap 创建一个带初始容量的 StringBuilder。
func NewStringBuilderCap(capnum int) *StringBuilder {
	builder := StringBuilder{
		buffer: *bytes.NewBuffer(make([]byte, 0, capnum)),
	}
	return &builder
}

// NewStringBuilder 创建一个空的 StringBuilder。
func NewStringBuilder() *StringBuilder {
	var builder StringBuilder
	return &builder
}

// NewStringBuilderString 根据给定字符串创建一个 StringBuilder。
func NewStringBuilderString(str *String) *StringBuilder {
	var builder StringBuilder
	builder.buffer.WriteString(str.ToString())
	return &builder
}

// Appendln 添加字符串并换行。
func (builder *StringBuilder) Appendln(s string) *StringBuilder {
	builder.buffer.WriteString(s + "\n")
	return builder
}

// Append 添加字符串。
func (builder *StringBuilder) Append(s string) *StringBuilder {
	builder.buffer.WriteString(s)
	return builder
}

// AppendRune 添加单个字符。
func (builder *StringBuilder) AppendRune(s rune) *StringBuilder {
	builder.buffer.WriteRune(s)
	return builder
}

// AppendStrings 添加多个字符串。
func (builder *StringBuilder) AppendStrings(ss ...string) *StringBuilder {
	for i := range ss {
		builder.buffer.WriteString(ss[i])
	}
	return builder
}

// AppendInt 添加整数。
func (builder *StringBuilder) AppendInt(i int) *StringBuilder {
	builder.buffer.WriteString(NewStringInt(i).ToString())
	return builder
}

// AppendInt64 添加 int64 类型的整数。
func (builder *StringBuilder) AppendInt64(i int64) *StringBuilder {
	builder.buffer.WriteString(NewStringInt64(i).ToString())
	return builder
}

// AppendFloat64 添加浮点数。
func (builder *StringBuilder) AppendFloat64(f float64) *StringBuilder {
	builder.buffer.WriteString(NewStringFloat64(f).ToString())
	return builder
}

// Replace 替换字符串中的指定内容。
func (builder *StringBuilder) Replace(old, new string) *StringBuilder {
	str := NewString(builder.ToString()).Replace(old, new)
	builder.Clear()
	builder.buffer.WriteString(str.ToString())
	return builder
}

// RemoveLast 移除最后一个字符。
func (builder *StringBuilder) RemoveLast() *StringBuilder {
	str1 := NewString(builder.ToString())
	builder.Clear()
	str2 := str1.Substring(0, str1.Len()-1)
	builder.buffer.WriteString(str2.ToString())
	return builder
}

// Clear 清空 StringBuilder。
func (builder *StringBuilder) Clear() *StringBuilder {
	var buffer bytes.Buffer
	builder.buffer = buffer
	return builder
}

// ToString 返回拼接后的字符串。
func (builder *StringBuilder) ToString() string {
	return builder.buffer.String()
}

// IsEmpty 判断 StringBuilder 是否为空。
func (builder *StringBuilder) IsEmpty() bool {
	return builder.buffer.Len() == 0
}